Wind is the flow of air in the atmosphere. Differences in air pressure cause the air to move from high pressure areas to low pressure areas. In a wind turbine, the wind is converted to 100 per cent renewable electricity.
The wind turbines convert the wind's kinetic energy into electrical energy. The wind causes the turbine's blades to rotate. This movement is converted into electricity in the generator located in the engine house at the top of the towers. From there, the electricity is passed on to the electricity consumers.
Wind turbines begin to produce electricity at low wind speeds up to a maximum wind speed that is usually around 25 meters per second, which corresponds to full storm strength. There, the turbines are taken out of operation so as not to damage important equipment.
The wind increases with the height above the ground, therefore tall wind turbines are built to make optimal use of the wind.
The wind power expansion has progressed strongly in Sweden and today we are one of the countries in Europe that has the most wind power in relation to the total energy production in the country.
With a planned phase-out of nuclear power, wind power is expected to play an even greater role in the future energy system. Large land areas, good wind conditions and a stable, deregulated electricity market mean that Sweden has good conditions for establishing large-scale wind power.
A modern wind turbine can produce up to 15–20 GWh per year depending on the wind conditions. That is enough to power around 1 000 Swedish homes per year.
Wind power is an entirely fossil-free source of electricity that creates no pollution. From a life cycle perspective, where the whole production and transport chain is taken into account, a wind turbine has offset its entire energy and material-related impact after around 6–8 months in production.
Holmen’s land is certified to the FSC® standard (FSC-ID), which means that we pay extra attention to our environmental impact in the areas where we establish wind power, and we never erect wind turbines in areas that have high conservation value or are key biotopes. The main negative impact that a wind turbine has on local wildlife relates to unavoidable collisions with birds and bats. According to a report by the Swedish Environmental Protection Agency, however, the risk is so small that it can be considered marginal in comparison with the impact of other human activities.
As a rule of thumb, wind turbines are generally placed at a distance of around 1 000 m from the nearest residence. This minimises shadow flicker, the immediate noise impact and the risk of injury from falling ice in winter. Some people feel that wind turbines have a negative impact on the look of the landscape, while others have a more positive attitude. Generally speaking, as knowledge of wind power’s climate benefits has grown, the positive attitudes have also increased.
The sound from a wind turbine is caused mainly by the large rotor blades as they move through the air. This creates a swishing sound that can sometimes be heard from quite a long distance. The perceived sound level is affected by many factors, such as the prevailing weather and wind conditions, the distance from the wind turbine and other sounds in the area. A sound level of 40 dBA (decibels) is used as the official standard for wind turbines located near a residential area.